A person who leads a change project or business-wide initiative by defining, researching, planning, building business support and carefully selecting volunteers to be part of the change team. Change agents must have the conviction to state the facts based on data, even if the consequences are associated with unpleasantness.
They must be people who have business knowledge, command respect, are well liked and have a real future in the company. Why? Because they are going to be re-designing processes that will deliver the future business, consequently they need to be the best people.